A known example of such a contact is disclosed in Japanese Patent Application Laid-open Publication No. 2006-19296. A contact section of the disclosed type of contact includes a spring section for pinching a mating contact to maintain a contacting state even when the mating contact moves relative to the contact.
Prior Art FIGS. 11A-11E show a contact according to a conventional technique which is illustrated together with manufacturing processes of the contact. Prior Art FIG. 11E shows the contact in a finished state, while Prior Art FIGS. 11A-11D sequentially show the manufacturing processes of the contact illustrated in Prior Art FIG. 11E. Here, the sequence of processes shown in Prior Art FIGS. 11A-11D is merely an example, and it is still possible to manufacture the contact shown in Prior Art FIG. 11E even in a different sequence of processes from those shown in Prior Art FIGS. 11A-11D.
A contact 900 according to the conventional technique is shown in Prior Art FIG. 11E. The contact 900 includes a U-shaped contact section 901, a pair of leg sections 902 to be brought into contact with a circuit board, and a pair of plate-like spring sections 904 which extend respectively from a pair of free-ends 903 provided on the contact section 901 toward the leg sections 902 while being bent at an angle of 180° in two positions along the way. The leg sections 902 are connected to the circuit board (not shown) by solder, and the U-shaped contact section 901 pinches a mating contact to establish electrical connection therewith. The contact 900 enables the contact 901 supported by the spring sections 904 to follow movements of the mating contact even when the mating contact receives an external force and moves in a direction in which the two free-ends 903 face each other.
The contact 900 is manufactured by punching and bending a conductive metal plate. To manufacture the contact 900, first a contact form 920 shown in Prior Art FIG. 11A is obtained by punching the metal plate. Although it is not illustrated in the drawing, the contact form 920 is connected with a lead frame that is formed together with the contact form 920 in the punching process. Next, this contact form 920 is bent along lines A, B, C, and D. To be more precise, two positions are bent at an angle of 90° along the line A (see Prior Art FIG. 11B) and then two positions are bent at an angle of 180° along the line B (see Prior Art FIG. 11C). Further, two positions are bent at an angle of 180° along the line C (see Prior Art FIG. 11D), and finally, two positions are bent at an angle of 90° along the line D to obtain the contact 900 shown in Prior Art FIG. 11E.
In the contact 900, it is necessary to bend the form at least six times along the lines A, B, and C in order to form the structure that allows the contact section 901 to pinch the mating contact and move so as to follow the movement of the mating contact. Moreover, it is necessary to bend the form four times along the line B and the line C at an angle of 180°, which requires more complicated processes than bending the form at the angle of 90°. Accordingly, the productivity of manufacturing the contact 900 is low.
Further, in the contact 900 according to the conventional technique shown in Prior Art FIGS. 11A-11E, the two free-ends 903 are to be located on both sides of the mating contact are directly connected to the different spring sections 904. Therefore, if vibration or impact is applied to the mating contact, a gap may be momentarily caused between the two free-ends 903 and the mating contact, which may result in breaking electrical connection therewith.
Further, the two free ends 903 that are to be located on both sides of the mating contact are directly connected to the different spring sections 904, respectively. Therefore, when vibration or an impact is applied to the mating contact, one of the two free ends 903 cannot follow the movement of the other one. Accordingly, a clearance may be momentarily generated between the two free ends 903 and the mating contact may be electrically disconnected from the conventional contact 900.
Still further, the contact according to the conventional technique shown in Prior Art FIGS. 11A-11E include the parts to be soldered in two positions and the parts are placed on the tip ends of the slender leg sections 902. Therefore, when connecting this contact by soldering, it is difficult to secure positional accuracy on the conductive part of the circuit board.